Eva Flo 1 *, Esther Garcés 1 , Jordi Camp 1

1. Land Uses Simplified Index (LUSI): a new and easy method to assess continental pressures to coastal and transitional waters Eva Flo1*, Esther Garcés1, Jordi Camp1

2. INTRODUCTION • The assessment of the anthropogenic pressures on the coastal zone is essential to develop management plans required for compliance of the Water Framework Directive • We need to work on: • identifiable inland pressures • which may be related to the coastal impact occurred • and that the pressure-impact relationships occur through known mechanisms • We must provide an objective, comparable and reproducible information and evaluation

3. RATIONALE A simple assessment of humanpressuresonthecoastalzoneisbasedonquantitativeevaluation of governmentcensus data orfromsatelliteimagesthatreflecttheland use, accordingtothefollowingprinciples: • Itisknownthatdifferentland uses generatedifferentqualities of inlandwaters, althoughthisisvery variable thereis a gradient of nutrientrichnessfromthecontributionsthatrangefrom a minimumtoland in its natural state up forurbanareas. Thegradientis: i) natural-rainfedagriculture ii) irrigatedagriculture iii) residential-industrial (veryvariable) iv) urban. Thisapplies to the area of influence of a particular stretch of coastwithout a river.

4. In thevicinity of a riverstreamflowthemainimpact are the uses itswatershed. Because of theWater Framework Directivethereis a direct control overthequality of riverwater, whichmakestheproblemeasyor at leasttakesittoanotherlevel of discussion. In the case of theinfluence of a riverover a sea areaiswellreflected in thefreshwatercontent, i.e. salinity. Fromherewehaveusedthetypology of thewatermasswith a high, lowor no riverinfluence. 3) The continental influenceismaximized in concaveareas of thecoast (a lot of landin a littlewaterpoured) and minimizingconvexareas (justpour in a lot of groundwater) whichsuggest a correction of thiskindbasedonthemorphology of thecoast. • From these principles, we constructed a simple index, LUSI, which can be applied from land use maps or satellite images (Google Earth).

5. METHODOLOGY • Land Uses Simplified Index (LUSI) is a specific combination of contiental pressures that influences a marine Water Body • The selected pressures are related to main characteristics and uses of land that could have an influence on phytoplanktonic growth: • Urban • Industrial • Agricultural (only irrigated land) • Rivers (Typology based on salinity is used) • Each pressure has been categorized in two or three categories and each category has a score.

6. For urban, agricultural (irrigated) and industrial pressures, categories have been created depending on the % of surface used for this activity. • For river pressure, categories have been created depending on salinity, thus each water body has been assigned a category depending on its typology. • An area comprised between the coastal line and 1,5 km inland and between the limits of each water body has been taken into account.

7. For each water body all scores are summed. Afterwards, a correction is applied to the sum in order to take into account the degree of confinement that could emphasize or diminish the effect of these pressures on the water body. Depending on the shape of the coastal line the sum is multiplied by the correction number: Finally LUSI is obtained as follows: LUSI= (Score urban + score agricultural + score industrial + score typology) * Correction number

8. CASE STUDY

11. Pressure-impact analysis Water bodies (Inshore) Significant if p<0.01 Acceptable if r < -0,8 or r > 0,8